1. Field of the Invention
The invention relates to electrical meters and in particular those which are mounted edgewise and have a face displayed along a narrow edge.
2. Description of the Prior Art
The edgewise indicating meter is very economical of panel space making it very popular in the compact equipment of today. However, this very compactness of modern equipment raises difficulties in access for repair and/or replacement. Thus, the meter housing and the way it is adapted for mounting become very significant.
Meter housings can be made like simple boxes in which the bottom of the box is itself the frame or supports the frame while the top of the box is a cover with sidewalls that extend in frictional contact outside or inside the sidewalls of the bottom. U.S. Pat. No. 3,155,906 to C. G. Roper discloses such a housing in which the walls of the box top extend inside the walls of the bottom. U.S. Pat. No. 3,497,806 to J. Nador et al. discloses an open frame design in which the entire meter movement is mounted within a frame formed of peripheral sidewalls. The frame is enclosed by a bottom cover which slides over the frame, a top cover which slides under lips formed in the upstanding sidewalls of the bottom cover, and a transparent end shield that provides a window for the meter face.
The more popular means for mounting meters to mounting panels have avoided the use of screw holes in the panels. Thus, it has been common to have some type of extendng rim or lip securely attached near the face of the meter whereby the body of the meter may be passed through a panel aperture from the front until it comes up against the rim. Then some form of clamping means is provided on the back side of the panel to hold the meter secure. Usually, this clamping means is separable and can be engaged to the meter body somehow after insertion since otherwise it would interfere with insertion of the meter through the panel.
U.S. Pat. No. 3,435,341 to A. A. Baron et al. discloses a mounting means in which lugs connect into recesses on each side of the meter housing and screws threaded through the lugs bear up against the inside of the panel to pull the exterior rim tightly against the panel.
Generally speaking, the prior art edgewise indicating meters have not been particularly easy to mount, disassemble or assemble. Housings have usually included a number of parts screwed or bolted together. Panel mounting has required juggling a number of pieces simultaneously while trying to tighten clamping screws.